1. Field of the Invention
The instant invention is generally related to climbing aids for rock climbers. More particularly, this invention is related to carabiners that link climbing aids together.
2. Description of the Prior Art
Climbers utilize rope, slings and a variety of mechanical devices as climbing aids to assist and protect their movement over rock. The climbing aids serve as a means to anchor the climber to the rock for the purpose of either preventing or arresting a fall.
A carabiner is a mechanical device used to link rope, slings and other climbing aids together. A carabiner is essentially a device used, for example, to attach a climber's body harness to the climbing rope. It is also used to link the climbing rope to anchors placed in or over the rock.
During a climb and especially in the event of a fall, the climber's safety is dependent on the security of numerous carabiner links. Consequently, it is imperative that every carabiner in the chain be able to withstand not only the weight of the climber but also the inertial forces generated when the rope arrests a fall.
A typical carabiner is palm sized, and either an oblong, oval or “D” shaped ring of a lightweight, high strength material, usually a heat-treated aluminum alloy. One side of the carabiner has a hinged arm that serves as an inward opening gate. The gate is spring loaded to remain normally closed. The normally closed, inward opening gate facilitates insertion of climbing aids such as rope or slings, but impedes inadvertent removal. Climbing aids are released from the carabiner by manually opening the gate.
There are two types of carabiner gates, wire gates and solid gates. A wire gate is a simple loop of corrosion-resistant spring-wire bent in a the shape of an elongated “U”. A solid gate is a short bar of a rigid high strength material, usually a heat-treated aluminum alloy.
The wire loop itself provides the closing force for a wire gate. This is accomplished by bending the legs of the “U” slightly off-parallel with unequal lengths, and bending the staggered ends 90-degrees inward. The wire loop must be slightly twisted for the ends to pass through correspondingly offset holes in the body of the carabiner. Twisting the wire loop causes a cantilevered spring force that holds the gate normally closed. Opening the wire gate additionally twists the wire which increases the spring force working to close the gate.
The closing force of a solid gate is provided by a stout compression spring that is housed within the gate. The spring axis is offset from a pivot pin so that the spring force is directed to close the gate. A spring link is employed to transfer the spring force to the carabiner body at an appropriate distance from the pivot pin. Opening the solid gate compresses the spring.
The opening end of the carabiner gate incorporates an interlocking mechanism that engages the carabiner body when the gate is closed. For wire gates the interlock is provided by the wire's looped nose mating with a hooked notch on the carabiner body. For solid gates the interlocking mechanism is typically a transverse pin that mates with a hooked notch on the carabiner body. Another popular configuration for solid gates is a keyed arrangement that mates a bulbous nose of the gate's opening end with a correspondingly shaped recess in the carabiner body. These interlocking arrangements allow a closed gate to carry part of the load imposed on the carabiner. Consequently, the carabiner is significantly stronger when the gate is closed. The ultimate strength of a carabiner with the gate open is typically 65% lower than with the gate closed.
Wire gate carabiners have several advantages over those with a rigid gate . Wire gate carabiners typically weigh less than rigid gate carabiners. Furthermore, a wire gate consists of only one working part, whereas a rigid gate is an assembly of at least four (4) parts: bar, spring, spring link, and pivot pin. The inherent simplicity of the wire gate makes it more reliable and less prone to problems of breakage, contamination or icing.
As the climber progresses upward, the carabiners in a protective chain of climbing aids often rub against the rock. Occasionally, a carabiner gate will catch on a rock or other object, or the rope itself, and may be temporarily pushed or pulled open without the climber's knowledge. Additionally, a carabiner can slap against the rock during a fall causing inertial loads that overcome the closing force of the spring and momentarily open the gate. Also, a rope moving rapidly through a carabiner during a fall can cause the carabiner body to vibrate sufficiently to shake the gate open.
Whenever the gate is opened, even momentarily, there is significant risk that a rope or other attached climbing aid will be inadvertently released. Furthermore, if a sudden load is applied to the carabiner at the instant that the gate is open, the ultimate strength of the carabiner will be significantly compromised and possibly fail. Such occurrences are well known by the climbing community and are considered a significant problem. Consequently, climbers pay careful attention to the placement and orientation of carabiners in order to minimize the chance of an inadvertent opening of the gate.
Climbers often use two carabiners joined by a short length of looped webbing, a combination called a quickdraw. One of the quickdraw carabiners is clipped to an anchor placed in or on the rock. The other quickdraw carabiner is clipped to the climber's rope. The quickdraw allows the rope to pull toward the centerline between staggered anchors thereby providing a less resistive path from the belay point to the climber.
A quickdraw requires the use of two carabiners to attach a rope to a single anchor. Assembling a quickdraw with smaller, lightweight carabiners minimizes the weight and bulk penalty of using two carabiners. Wire gate carabiners are often used for quickdraw configurations because they weigh less than solid gate carabiners.
A properly placed quickdraw may have the additional benefit of reducing the chance of an inadvertent opening of the gate. Unfortunately this is often not the case. For example, if the rope is incorrectly threaded through the carabiner, a moving rope can twist the carabiner and expose the gate to a sideward opening force. Also, if the rope is pulled across or around the gate, the gate can be inadvertently opened.
A climber must be very careful when placing and clipping into a quickdraw. The dangling carabiner (the carabiner that will be clipped to the climbers rope) must be oriented so that its gate is away from the rock face. When the rope is clipped in, it must run along the spine of the carabiner, not across the gate.
Many solid gate carabiners have a bend to facilitate clipping the rope. The bent gate's center is curved inward slightly which allows the gate to open wider and serves to guide the rope to the opening end. Bent gate carabiners are often used as the dangling carabiner of quickdraw configurations.
Placing the rope into the quickdraw's dangling carabiner requires skill and dexterity. Usually the climber is hanging on to the rock surface with one hand, and has only one hand free to clip in the rope. Depending on which hand is free, and the location and orientation of the carabiner relative to the climber, a variation of two techniques is typically used: 1. The carabiner is stabilized with the middle finger, and the rope is clipped in with the thumb and index fingers; or 2. Stabilize the carabiner with the thumb, and clip the rope using the index and middle fingers. No matter the technique used, the carabiner gate must open easily and without hesitation.
There are situations where the risk of an inadvertent opening of the gate is totally unacceptable, For example, the carabiner used to attach the climbing rope to the climber's body harness must never open inadvertently. Similarly, the carabiner used to attach a belay device to the climber's harness must never open inadvertently. Consequently, harness attachments and the like require greater security, for example, two parallel carabiners or a single carabiner with a locking gate.
Greater security can be obtained by using two carabiners side-by-side with the gates opening in opposite directions. However, extra carabiners solely for the purpose of parallel placement are undesirable because they double the weight and bulk that the climber must carry.
To avoid the need for side-by-side carabiners, various mechanical means have been developed to lock solid gates closed. For example, a popular locking configuration incorporates a sleeve that is threaded, nut like, to the gate. The sleeve can be screwed along the length of the gate, either toward the hinge, or toward the opening end. The sleeve is screwed into the locking position after the rope or other climbing aids have been clipped into the carabiner and the gate closed. In one configuration the gate is locked by screwing the sleeve until it crosses the opening end of the gate and moves over or jams against the adjacent body of the carabiner. In an alternate configuration the gate is immobilized when the sleeve is screwed over the hinge. Locking or unlocking a carabiner with a threaded sleeve is not instantaneous, that is, it takes time to thread the sleeve from the unlocked position to the locked position and the reverse.
Threaded locking sleeves undesirably add bulk and weight to the carabiner. Threaded locking sleeves are also inherently troublesome. The threads can become clogged with dirt or ice. The sleeve can inadvertently screw out of the locked position when the carabiner rubs across the rock. Furthermore, the gate and threaded sleeve mechanism require precise machining and assembly alignment, both of which add to manufacturing cost.
Other solutions of the prior art include solid gates equipped with spring loaded sliding and/or rotary sleeves called auto-lockers. Sliding and/or rotary sleeves function similarly to threaded sleeves, and are designed to lock automatically and nearly instantaneously when the gate closes. Sliding and rotary sleeves share the same problems as threaded sleeves, and are especially costly to manufacture. A critical problem of auto-lockers is that the gate can jam and not correctly close.
The increased bulk, weight and expense of the prior art limits the number of locking carabiners that a climber carries during a climb or is willing to buy. Consequently, there may be situations during a climb when the climber is compelled to use a non-locking carabiner although a locking type would be preferable or safer.
The security of quickdraw applications would benefit from the use of locking carabiners, but most quickdraw configurations utilize at least one wire gate or bent gate carabiner. Due to its wire construction, threaded or sliding/rotary sleeves cannot be incorporated on wire gate carabiners. And the bend interferes with mounting locking sleeves on bent gates. The prior art only has the means to lock a straight gate closed.
Quickdraw configurations do not incorporate state-of-the-art locking straight gate carabiners because they are considered too heavy and bulky for this application. The need to be able to easily and instantly clip a rope using only one hand make auto-locking gates especially inappropriate for quickdraw use.
The instant invention is a locking means ideally suited for quickdraw applications because it adds negligible weight and bulk to the carabiner and can be incorporated on bent gate, straight gate and wire gate configurations. The instant invention is a locking mechanism that can securely, reliably and quickly lock a carabiner gate by flipping a short lever with a fingertip. Furthermore, compared to state-of-the-art locking means, the instant invention is less susceptible to jamming and is easily manufactured.